Excess-wattmeter.



A. w. BURKg. EXCESS WAUMETER.

APPLICATION FILED FEB.24,1916.

l ,284,23 l Patentod Nox'. l?, 1918.

(URE

Mild

' pplication flied February 24, 1916.

y f l attacca/acera: known. tnat l, Amano "v. BURKE, o'r` the King of Great Britain, re-

t 1dlilniin ton, in the county of New State ol Delaware, have 'invented new and useful improvements iu ess Vattnieters, or which the following a soeciication. This invention relates to recortliiu;v watters such as are used on alterriatinp,r cur- Mits, for recording,r the electrical mcd in excess ot a ceri ain pree iantity, and is an improveaient u, in the inventions described in my copian-ding applications Serial No, 313,494, i'iled anuary 2l, 19M; Serial No. 11,484, tiled March 2, 1915; Serial No. 46,974, liled August 23, 1915 ,Zand Serial No. 64,990, filed Deceniberl, i915.

7Lillie object ci my invention is to produce a meter that will record only the excess energy used over a predetermined quantity and that is substantially unallected in acturacy by ordinary changes in line Voltage.

n s result is accomplished by the use of yially designed transformer, called a pensator, the magnetic circuit ci which normally operated at a flux density far above its magnetic saturation point, The endary current from trie compensator 1s ereitore substantially constant regardless of changes in the primary current above a certain minimum. rl`his secondary current used to produce a constant negative torque en the meter, which however is prevented from reverse rotation as described hereafter, whereby the consumerls current is not re- :orded whenV it is equal to or less in value than the compensator secondariY current; any current consumed in acess of this value overcomes the negative torque ot' the coniato'r secondary current, and is recorded by the meter. l "i the accompanying dranf'ingsr-A libere l 1s a curve showingjahe relative current strengths ia the primary and secondary circuits o1 a compensator, the point 'intera ction of the curves reinescnting 'he point of magnetic saturation of the core;

r. 2 illustrates one type of intermittent Speccaticn of Letters atent.

atented Nov. .1.2, li.

Serial Eo. 80,201.

showing; different niethodsof connecting and (i. but including' ay relay to open and close the potential circuit of the meter; and

Fig. S) is a view of a three-wire circuit provided with an excess meter.

ln Fig: l, curve A indicates the range of current in the primary of a compensator due to changes in the load; and with constant load, due to fluctuation in line volt` age. Curve B indicates the variation in current induced in the secondary of the compensator by the variable primary current. The currents have equal values at the point of intersection, X, which is the point of magnetic saturation oi the core. it will he noted that above X the increase 1n current in the compensator sec-v ondary (curve B) is practically negligible, while below X the current drops off quite rapidly. ln p notice, the compensator is operated under such conditions that with normal loads the current in the secondary li always above the point of intersecin Fig. 2, the armature shaft 21 of the meter carries a suitable intermittei'itegrip device such as a ratchet-Wheel 22 and a pawl 23, the intermittent-grip pern'iittiincr rotation of the meter in one direction only, and thereby preventing negativev recording.

ln Fig. 3, current from the supply mains ent xrs the house service mains 31. having connected in series therewith the primary ofthe compensator the latter also provided With a secondary 34. The house current also passes through the watt-meter lcontainingl the .series coil 3G and the potential coil 38, and through the translating devices ln cooperative relation with the series coil 3G in its action upon the wattmeer, is the suitably located balancing or neutralizingf coil 37, connected to the secondary 3l of the compensator through the adjustable resistance R, which latter may be of the inductive or non-inductive type. The

instantaneous directions of all currents flowcompensator explained under constant tially constant in value, as Fig. 1, and hence this coil exerts a negative torque upon the meter. equal to the Value of the contracted-for load. Any current consumed in excess of the contractedfor load exerts a proportional positive torque through the series coil, and operates the meter accordingly. With loads equal to or below the contracted-tor value, the current flowing through the series coil 36 of the watt-meter exerts a weaker torque than that ot the balancing` coil 37; the meter would therefore rotate in the reverse direction, except .that it is checked by the intermittenbgrip device shown in Fig. 2 or by other means; consequently no record is made of such loads. The meter record is therefore proportional to the excess load only.

Fig. 4 resembles Fig. 3, except that the secondary 43 of the compensator 42 is connected to the terminals o't the series coil 46 in the watt-meter 45. The circuits lare connected so that currents flow as indicated by the arrows, and as a result, no current flows through the series coil 46 when the load on the house circuit equals the contracted-tor value. lWith increased loads, a current proportional to the increase energizcs the series coil 46 and actuates the meter accordingly; with decreased loads, a current from the compensator secondary 43 energizcs the series coil and tends to reverse the meter, but is checked by the intermittent-grip device shown in Fig. Q, or by other means. The meter, therefore, records only the load in excess of the predetermined quantity.

Fig. 5 resembles Fig, 3, except that the potcntia coil 51 of the watt-meter 5'2 is connected to the secondary 55 ot the compensatorI 53, the primary 54- ot the compensator being connected in shunt across the mains 50. ln this case, the compensator 53 delivers a substantially constant voltage to the potential coil 51 ot' the watt-meter, and it is therefore unaffected by ordinary changes in line voltage. The operation ot the meter is otherwise the same as with Fig. 3.

Fig. 6 rcscn'ibles Fig. 4, except that the potential coil 61 ot the watt-meter 62 is supplicd by the secondary 65 of the compensator (33. as in Fif. The operation is otherwise the saine as described under F 4 and 5.

Fig. 7 resembles Fig. 4, except that the service line is connected in series with the magnet 71 otl the relay 72, the armature 73 of which is retracted by the :uljustable spring 74, and only pci-mits the contacts 75 to be closed when the load current circulating through the magnet 71 exceeds the contracttal-for value. llpon closing thc contacts 75. the circuit is completed through the potential coil 7G ot' the meter 77; the latter then operates as described under Fig. 4. lVhen the load is lessthan thc cohtracted-l'or value,

Leases?.

the relay does not operate, and contacts 7 5 remain open; the meter therefore does not operate. The relay 72 is used in place of the intermittent-grip device shown in Fig. 2.

Fig. 8 resembles and operates like Fig. 6 in all respects, except that a relay 81 is included in the circuit of the potential coil 82 of the watt-meter S3. The relay operates as described r. ider Fig. 7.

In Fig. 9, current from the three-Wire supply mains 99 traverses the primary coils 92,

93 of compensator 91, and the series coils' 96, 97 ot' the three-wire watt-meter 95, and also the. loads 9S, 99, the return circuit of which is connected to the neutral wire. T he secondary 94 of the compensator is connected to one ot' the series coils of the watt-meter, Jfor example coil 9G: The watt-meter 95 is also supplied with the shunt coil 100, connected across the outer supply mains 30. The compensator 91 is so constructed that its magnetic circuit is not saturated until the predetermined loads 9S, 99 on both sides of the house circuits are being consumed; and is further constructed so that itsratio of conversion is greater than 1:1, When the magnetic circuit is not saturated. lVith the predetermined load on the house mains, the magnetic circuit is saturated, and the ratio ol' conversion is then 1:1, and with excess loads, the current in the compensator secondary 94 does not increase, as explained under Fig. 3.. `When less than the full loads 9S, 99 are being consumed, thc meter tends to reverse, duc to thc torque of the negative compensator current, but is checked by a de vice such as illustrated in Fig. '2, or the shunt coil 100 of watt-meter 95 may have a relay, such as shown in connection with Figs. 7 and S. lVhen the predetermined load is reached, the ratio of conversion in the compensator is 1:1. and the torques due to the series coils 9G. 97 are balanced by the torque of the compensator sccondar i 94; the meter there- Jorc does not tend to rotate. lith increased loads, the excess current exercises a torque depending upon the excess current, and the meter is actuated accordingly. The compensator 91 is shown provided with one secondary 94, which is connected to the series coil 9G. the series coil 97 not being connected thcrcto. The energy delivered by the sec'- ondary 94 is su'liicient to not only balance the .series coil 99, but also coil 97 so long as thc magnetic circuit ot the compensator is not Ysaturated; upon reaching` saturation. regardless ot' the distribution ot' the load in circuits 9S. 99. the excess current is registered. rFlic compensator could be provided with two sccoudarics. one of which should be connected to scrics coil 96. and the other to coil 97; or two cmnlwnsators could be used in placi` of one, in which case they would be connected in the usual Way to`the outside mains. While F ig. 9 shows the secondary `vention to appl)Y the relay to connections as shown in Figs. 3, and 9.

l. An alternatingY current electric meter having a series coil, in combination with a compensator ha ring its primary coil atlapted to be energized by current tlow in thel service mains in which the meter is adapted to be connected and its secondary coil electrically connected to prevent the production ot' a positive torque by the series coil ot' the meter until the current flow in the service line exceeds a predetermined strength.

:2. An alternating current electric meter having a potential coil and a series coil, in combination with a compensator having its primary coil adapted to be energized by current llow in the service mains in which i the meter is adapted to be connected and its secondary coil electrically connected to prevent the production of a positive torque by the series coil of the meter until the current flow in the service line exceeds a predetermined strength, and a second compensator havingr its vpriniary connected across the supply circuit, and means for energizingthe potential coil of the meter by current of substantially constant voltage from the secondary of said second compensator.

3. ln an electric meter. the combination ot a compensator and a series coil in said meter, the primary coil ot said compensator connected in Series with the service line and the series coil of the meter. and the secondary of said compensator connected to the seriesI coil in said meter.

l. ln an electric meter, the, combination of a compensator and a series coil in said meter, the primary coil oli said compensator connected in series with the service line and the .series coil of the meter, and the second.- ary oi said conn'iensator connected tothe series coil in `said meter, and means to prevent negative recording oi said meter.

5. ln an electric meter. the combination ot a compensator, coils in said meter, a po# tcntinl coil in said nait-imiter, the primary coil of said compensator connected in series v 'ith he servire line, the secondary ot said .omiensator connected to a coil in said meter. a second compensator, the primary ol" which is connected in multiple with theA and means to prevent negative recording of said meter.

7. ln an electric meter, the combination of a compensator, a series coil in said meter, a potential coil in said meter, the primary coil of said compensator connected in series with the service line and the series coil of the meter, the secondary of said compensator connected to the series coil in said meter, a second compensator, the primary. of which is connected in multiple with the service line, and the secondaryf of Which is connected to the potential coil of the meter.

8. ln an electric meter, the combination of a compensator, a series coil in said meter, a potential coil in said meter, the primary coil of said compensator' connected in series with the service line and the series coil of the meter, the secondary of said 'compen` sator connected to the series coil in said me ter, a second compensator, the primary of which is connected in multiple -With the service line, and the secondary of which is connected to the potential coil of the meter, and means to prevent negative recording of said meter.

9. An electric meter comprising in combination a rotatable armature, electromagnetic means for producing a magnetic field adapted to rotate said armature at a speed which is a function of the rate of consumption of electric energy, means responsive to the rate of consumption of electric energy for negativing the effect of said first mentioned means while the rate of consumption of energy is less than a predetermined value and for oll'ering a substantially constant opposition to such first mentioned means while the rate 'of consumption of energy equals or exceeds said predetermined value, and means for registering the revolutions of said armature.

ln testimony whereof l my signature in presence of two Witnesses.

ALFRED W'. BURKE.

Vlitnesses:

EMMA Snnrrsitr, RUTH lVl. TnAwLnY.

lt is hereby certified that in Letters Patent No. 1,284,231,-grantedNovember 12, 1918, upon the application of Alfred W. Burke, of Wilmington, Deiawere, for an improvement in Excess-VVettme-ters,77 an error appears in the printed specification requiring correction as folows: Page 3, line 55, claim 5, and line 65, Claim 6,

for the compound Word Wett-meter read meter; and that the said Letters Patent should be reed with this correction therein that the same may conform to the record of the ease in the Patent Office.

signed and Sealed this 24th day of December, A. D., 191s.

[SEAL] F. CLAY,

Acting Commissioner of Patents; 

